Function declaration syntax in Kotlin - Mini Project: Build & Apply

Function declaration syntax

📖 Scenario: You are learning how to write simple functions in Kotlin. Functions help you organize your code into reusable blocks that do specific tasks.

🎯 Goal: Create a Kotlin function that adds two numbers and returns the result.

📋 What You'll Learn

Declare a function named addNumbers that takes two Int parameters named a and b.

The function should return an Int which is the sum of a and b.

Call the function with the numbers 5 and 7 and print the result.

💡 Why This Matters

🌍 Real World

Functions help programmers organize code into small reusable pieces, making programs easier to read and maintain.

💼 Career

Knowing how to write functions is essential for any software developer to build clean and efficient code.

1

Create the function header

Write a function declaration named addNumbers that takes two Int parameters called a and b. Do not write the function body yet.

Kotlin

// Write the function header for addNumbers with parameters a and b
// Your code here

Need a hint?

Start with the keyword fun, then the function name, parameters in parentheses, and the return type after a colon.

2

Add the function body

Inside the addNumbers function, write code to return the sum of a and b.

Kotlin

fun addNumbers(a: Int, b: Int): Int {
    // Add code to return the sum of a and b
    // Your code here
}

Need a hint?

Use the return keyword followed by a + b.

3

Call the function

Call the addNumbers function with arguments 5 and 7 and store the result in a variable named result.

Kotlin

fun addNumbers(a: Int, b: Int): Int {
    return a + b
}

// Call addNumbers with 5 and 7 and store in result
// Your code here

Need a hint?

Use val result = addNumbers(5, 7) to call the function and save the answer.

4

Print the result

Write a println statement to display the value of the variable result.

Kotlin

fun addNumbers(a: Int, b: Int): Int {
    return a + b
}

val result = addNumbers(5, 7)

// Print the result
// Your code here

Need a hint?

Use println(result) to show the sum on the screen.